Italian police seized a number of iron bars, baseball bats and catapults from demonstrators arriving by coach for the start of the "No" rally at the Piazza Repubblica, but the rally remained largely peaceful.

Italian PM Matteo RenziCredit:
ANSA

People chanted “thieves, thieves” and blasted red smoke bombs outside the Treasury ministry, as the march snaked past some of the 800 police officers deployed for the event.

Security fears were heightened after a suspected anarchist bomb attack on a police station in Bologna yesterday/SUN morning, that damaged the building but caused no injuries.

People march behind a banner portraying Italian premier Matteo Renzi and reading "Let's oust Renzi" during the demonstration in Rome ahead of a referendum over a constitutional reformCredit:
AP

“We say ‘No’ to power in the hands of the few, no to privileges for those who don’t represent us,” said Stefano, aged 24, one of the throng of young people on the march.

“From schools, universities, piazzas and markets people are speaking out against reforms that have been decreed on high. Democracy is participation, that’s why we say we want power for the people.”

Students waved banners saying “Renzi get out,” and “the people say no to a disgusting constitutional reform.” Mr Renzi has promised to resign if he loses the ballot over his proposal to reduce the role of the Senate and transfer powers to central government from the regions.

The demonstrators are against the reform approved by the government of Matteo RenziCredit:
AP/Andrew Medichini

“On Dec. 5 Italy will have to go forward with everyone together,” Mr Renzi told the Domenica Live television programme on Sunday.

“I think it is best if we go forward quickly, but in any case we must go forward together.” Organisers said that 50,000 people took part in the march, despite what they claimed was obstruction by the authorities.

“They did everything to try and throw a spanner in the works,” said Marta Rossi. “From imposing a roundabout route instead of allowing us to go through the city centre to asking for €6,000 for a clean-up.”